Struct Extensions 

pub struct Extensions { /* private fields */ }

Available on crate feature extensions only.

A type map of protocol extensions.

It is heavily inspired by the Extensions type from the http crate.

The main difference is that the inner Map is wrapped with an RwLock to allow concurrent access.

This is necessary because Extensions are shared between all the threads that handle the same socket.

You can use the Extension or MaybeExtension extractor to extract an extension of the given type.

Implementations

impl Extensions

pub fn new() -> Extensions

Create an empty Extensions.

pub fn insert<T: Send + Sync + Clone + 'static>(&self, val: T) -> Option<T>

Insert a type into the Extensions.

The type must be cloneable and thread safe to be stored.

If a extension of this type already existed, it will be returned.

Example

let mut ext = Extensions::new();
assert!(ext.insert(5i32).is_none());
assert!(ext.insert(4u8).is_none());
assert_eq!(ext.insert(9i32), Some(5i32));

pub fn get<T: Send + Sync + Clone + 'static>(&self) -> Option<T>

Get a cloned value of a type previously inserted in the Extensions.

Example

let ext = Extensions::new();
assert!(ext.get::<i32>().is_none());
ext.insert(5i32);

assert_eq!(ext.get::<i32>().unwrap(), 5i32);

pub fn remove<T: Send + Sync + 'static>(&self) -> Option<T>

Remove a type from the Extensions.

If a extension of this type existed, it will be returned.

Example

let mut ext = Extensions::new();
ext.insert(5i32);
assert_eq!(ext.remove::<i32>(), Some(5i32));
assert!(ext.get::<i32>().is_none());

pub fn clear(&self)

Clear the Extensions of all inserted extensions.

Example

let mut ext = Extensions::new();
ext.insert(5i32);
ext.clear();

assert!(ext.get::<i32>().is_none());

pub fn is_empty(&self) -> bool

Check whether the extension set is empty or not.

Example

let mut ext = Extensions::new();
assert!(ext.is_empty());
ext.insert(5i32);
assert!(!ext.is_empty());

pub fn len(&self) -> usize

Get the number of extensions available.

Example

let mut ext = Extensions::new();
assert_eq!(ext.len(), 0);
ext.insert(5i32);
assert_eq!(ext.len(), 1);

Trait Implementations

impl Debug for Extensions

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Extensions

fn default() -> Extensions

Returns the “default value” for a type.